Question

The number of ways in which $r$ letters can be posted in $n$ letter boxes in a town is

• A. $n^r$
• B. $r^n$
• C. $^nP_r$
• D. $^nC_r$

Answer 1

Answer: (A)

$n^r$

Answer 2

Since every letter can be posted in $n$ ways [$\because$ no of letter boxes = $n$ ] $\therefore$ total number of ways for $r$ letters $=\frac{n\times n\times......\times n}{r factors}$ $=n^{r}$